The invention relates to capacitive acceleration sensors capable of being implemented in a small volume and is particularly applicable in all areas of industry where the use of low cost miniature sensors is necessary.
The invention relates particularly to sensors of the type comprising an insulating substrate supporting a first measurement electrode and comprising a flexible measurement arm of semiconductor material, one end of which is secured to the substrate and the other end of which constitutes a second electrode facing the first electrode, flexibility of the arm allowing the second electrode to be displaced towards and away from the substrate in response to acceleration in a direction transverse to the electrodes.
Such sensors are known in which the first end of the flexible arm is enlarged and secured to the substrate by, for example, soldering. The difference in thermal expansion between the substrate, which is usually constituted by a metal oxide such as alumina, and the arm, constituted for example by silicon, causes modification in the rest angle of the arm relative to the substrate and therefore in the capacitance of the capacitor formed by the electrodes. It is difficult to compensate precisely for this zero shift.